Deformation micromechanics of lyocell fibres subjected to tensile strain

The deformation micromechanics of strained lyocell fibres has been studied using Fourier-transform infrared (FTIR) spectroscopy and wide-angle X-ray diffraction (WAXD) technique. For applied strain of up to 10%, the FTIR study shows effects across the entire spectral range, particularly in the frequency regions corresponding to O-H stretching and C-O-C deformation. The recorded features include changes in both relative intensities and band position. The data suggest that the deformation micromechanics may involve H-bond deformation, rupture and re-formation. The WAXD study does not reveal any measurable crystal strain corresponding to the applied strain, indicating that at the micro-level the deformation is concentrated in the inter-fibrillar regions. On the other hand, the WAXD data show a decrease in crystallinity upon stretching the fibres.